1. Field of the Invention
This invention relates to an improved low-cost, low-energy-consuming incandescent tubular lamp which provides increased light efficiency.
2. Description of the Prior Art
An incandescent tubular lamp which is low-cost, low-energy-consuming and which provides increased light efficiency is particularly desirable now, when there exists a good deal of public concern about conservation of energy.
Incandescent tubular lamps of a variety of types are well known in the art.
U.S. Pat. No. 2,931,933 discloses an incandescent lamp with an interior reflective coating for reflecting the light emitted from the incandescent filament.
U.S. Pat. Nos. 3,012,167 and 3,080,497 disclose tubular incandescent lamps with pin terminals.
U.S. Pat. No. 3,073,986 discloses a tubular lamp with a double coil incandescent filament supported by spaced metal discs.
U.S. Pat. No. 3,891,885 discloses an incandescent lamp in which a coil filament is supported in an envelope by support wires.
None of the above patents utilizes the modifications in structure of the lamp for the purpose of obtaining a low-cost, low-energy-consuming, high-efficiency incandescent tubular lamp.
Other relevant patents are U.S. Pat. Nos. 2,068,423; 2,964,668; 3,040,204; 3,091,718; 3,930,178; 3,943,395; 3,953,757; 3,982,145; and 4,179,639.